Process for breaking petroleum emulsions



Patented July 1, 1952 UNITED PROCESS FOR BREAKING PETROLEUM EMULSIONS NoDrawing. Application March 5, 1951, Serial No. 214,005

' Claims. 1

This invention relates to petroleum emulsions of the water-in-oil typethat are commonly referred to as cut oil, roily oil, "emulsified oil,etc., and which comprises fine droplets of naturally-occurring waters orbrines dispersed in a more or less permanent state throughout the oilwhich constitutes the continuous phase of the emulsion.

One object of my invention is to provide a novel process for breaking orresolving emulsions of the kind referred to.

Another object of my invention is to provide an economical and rapidprocess for separating emulsions which have been prepared undercontrolled conditions from mineral oil, such as crude oil and relativelysoft waters or weak brines. Controlled emulsification and subsequentdemulsification under the conditions just mentioned, are of significant.value in removing impurities particularly inorganic salts from pipelineoil.

Demulsification as contemplated in the present application includes thepreventive step of commingling the demulsifier with the aqueouscomponent which would or might subsequently become either phase of theemulsion, in absence of such precautionary measure. Similarly, suchdemulsifier may be mixed with the hydrocarbon component. v

The demulsifying agent employed in the present process is a fractionalester obtained froma polycarboxy acid and a diol obtained by theoxypropylation of a dihydroxy ether of glycerol. This glycerol ether isobtained by reacting one mole of hexyl alcohol, C6H13OH, with one moleof glycide, or any comparable procedurewhich produces the same compoundor equivalent isomer thereof.

Various hexyl alcohols areobtained commercially such as methyl amylalcohol, Z-ethylbutanol, and hexanol. The initial reaction with glycidetakes place more rapidly and more satisfactorily with a primary alcohol.For this reason I'prefer to use a primary hexyl alcohol as the startingmaterial and particularly to use normal hexanol. These particularalcohols are available from various sources. My preference is to treatthe glycerol ether of a suitable hexyl alcohol with sufiicient propyleneoxide so the resulting productis not completely water soluble, i. e., isat least emulsin-able or insoluble in waterand alsojso the product is nolonger completely insoluble in kerosene, i. e., tends to disperse or issoluble inkerosene.

The solubility of the hexyl alcohols in water is comparatively limited,for example, from approximately .6 of 1% to less than 2%. However, theethers obtained from glycerol are distinctly more soluble and areappropriately considered watersoluble in the ordinary sense. .Suchether, of course, need not be obtained necessarily by the use of glycidebut could be obtained by the use of glycerol monochlorohydrin. Theinitial alcohols used as satisfactory materials are soluble in kerosene.This solubility is diminished, in fact, practically disappearsafterconversion into the glycerol ether. Stated another way, the initialglycerol ether is water-soluble to a significant degree andsubstantially kerosene-insoluble.

In the hereto appendedclaims reference to the product beingwater-insoluble means lack of solubility either by being onlydispersible, emulsifiable, or rapidly settling out in layers, or forthat matter completely insoluble in the usual sense. The intention is todifierentiatefrom an ordinary soluble substance. Similarly, reference in-the claims to being at least kerosene-dispersible mean that the productwillat least disperse or emulsify in kerosene or may be completelysoluble in kerosene to give a clear, transparent, homogeneous solution.I

As stated, the monohydric alcohol has the following structure:

CeHnOI-I The glycide derivative is of the following structure:

It is this latter compound which is subjected to oxypropylation.. Iffor, convenience the latter compound i indicated thus: HOR'OH theproduct obtained by oxypropylation may be. indicated thus:

mocha) ton'occanem an with the proviso that n and 11." represent wholenumbers which added together equal a sum varying from 15 to 80, and theacidic ester obtained by reaction of the polycarboxy acid may beindicated thus:

in which the characters have their previous sigwater-insoluble orwater-dispersible, and kero- I sene-soluble or kerosene-dispersible.

Attention is directed to the co-pending application of C. M. Blair, Jr.,Serial No. 70,811, filed January 13, 1949, now Patent 2,562,878, grantedAugust 7, 1951, in which there'is described, among other things, aprocess for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of anesterification product of a dicarboxylic acid'and a polyalkylene glycolin which the ratio of equivalents of polybasic acid to equivalents ofpolyalkylene glycol is in the range of 0.5 to 2.0, in which the alkylenegroup hasfrom 2 to 3 carbon atoms, and in which the molecular weight ofthe product is between 1,500 to 4,000. 7

Similarly, there have been used esters of dia single hexyl alcohol butone could employ.

I either one of two ways.

carboxy acids and polypropylene glycols in which 2 moles of thedicarboxy acid ester have been reacted with one mole of a polypr pyleneglycol having a molecular weight, for example, of 2,000 so as to form anacidic fractional ester. Subsequent examination of what issaid herein incomparisonwith the previous example as well as the hereto appendedclaims will show the line of delineation between such somewhatcomparable compounds. Of greater significance, however, is what is saidsubsequently in regard to the structure of the parent diol as comparedto polypropylene glycols whose molecular weights may vary from 1,000 to2,000. I v

- For convenience, what is said hereinafter will be divided into fiveparts: 7

Part 1 will be concerned with the preparation of the diol by reacting ahexyl alcohol with glycide or its equivalent.

Part 2 will be concerned with the oxypropylation of the diol obtained inthe manner previously described in Part 1;

Part 3 will be concerned with the preparation of esters from theaforementioned oxypropylation derivatives; 7

Part 4 will be concerned with the structure of the herein describeddiols and their significance in light of what is said subsequently.

Part 5 will be concerned with the use of the products herein describedas demulsifiers for breaking water-in-oil emulsions.

PART 1 As previously pointed out he monohydric compound is a hexylalcohol having the formula CsHraQH. However, a variety of isomers may beemployed, such as (CH3)2CHCH2CH(OH) CH3, (CzHs) zCHCHzOH, 01 CH3(CH2)4CH2OH. Such compound is then reacted with a suitable reactant such asglycide to give a dihydroxy compound. This reaction may be shown thus:(C1H5)2CHCHOH anon-05 0B,

( z sh flzOoaHs If normal hexanol is used the reaction is, of

4 course, substantially the same except that an isomer is obtained,thus:

onxompomooin,

In examining the above reaction it is obvious an isomeric mixture couldbe obtained for a number of reasons. One need not necessarily employvarious isomers as noted, or a mixture of isomers.

Any isomers or mixtures of isomers could then be reacted with glycideand again the epoxy ring could open, depending on the catalyst used, in

Therefore, when reference is made to the dihydroxy compound obtained forconvenience from hexyl alcohol by reaction with glycide or theequivalent it is immaterial which isomer is available or whether amixture of isomers is used. a

As far as, forming the dihydroxy compound is concerned other reactionscan be employed which do not involve glycide; for example, one canproduce ethers of the kind hereinemployed by use of a glycerolmonochlorohydrin, i. e., either alpha or beta glycerol monochlorohydrin.Attention is directed again to the fact that in the previous formula andin the formulas in the claims it would be immaterial whether the freehydroxyl radicals prior to esterification are present as attached to thefirst and third terminal carbon atoms, or second and third carbon atoms.This is simply an isomeric difference depending on how theepoxy ring isruptured in the case of glycide, or whether one employs glycerol alphamonochlorohydrin or glycerol beta monochlorohydrin. Other suitableprocedure involves the use of epichlorohydrin in a conventional manner.For instance, the oxyprop-ylated compound can be treated withepichlorohydrin and the resultant product treatedwith' caustic soda soas to reform the epoxy ring The epoxide so'obtained can then be treatedwith water so as to yield a com,- pound having two hydroxyl radicalsattached to two of the three terminally adjacent carbon atoms. s I

Attention is directed to the fact that the use of glycide requiresextreme caution. This is particularly true on any scale other than smalllaboratory or semi-pilot plant operations. Purely from the standpoint ofsafety in the handling of glycide, attention is directed tothefollowing: (a) If prepared from glycerol monochlorohydrin, this productshould be comparatively pure; (b) the glycide itself should be as pureas possible as the efiect of impurities is difiicult to evaluate; (c)the glycide should be introduced carefully and precaution should betaken that it reacts as promptly as introduced, 1. e., that no excess ofglycide is allowedto accumulate; (d) all necessary precaution should betaken that glycide cannot polymerize per se; (6) due to the high boilingpoint of glycide one can readily employ a typical separatable glass ing;or better still, through an added opening at the top, the glass resin.pot or comparable. vessel should be equipped. with a. stainless steelcooling coil so that the pot can be cooled more rapidly than by mereremoval of mantle. .If. a. stainless .steel coil is introduced it means:vthatlthev conventional stirrer of the paddle type is' changed into thecentrifugal type which causes the fluid or reactants. to mix due toswirling action in the center of the pot. Still betteris the'use of alaboratoryautoclave of: the kind previouslydescribed in this Part; butin any event when the initial amount of: glycide. is added to a suitablereactant, the speed of reaction should-be controlled by; the usualfactors, such. as (a) the addition of glycide; (b) the eliminationofexternal heat; and (c) the use of cooling coil-so there is no undue risein temperature. All the foregoing is merely conventional but is includeddue to the hazard in handling; glycide;

Example 1c The. equipment used was a glass resin pot of the kinddescribed above. Into this resin pot were charged 5 gram moles of normalhexyl alcohol. This represented 511 grams- To this there was addedapproximately 1% of sodium methylate equivalent to 6 grams. Thetemperature of the reaction mass was raised to 121 -C. 5 moles of.glycide, equivalent to 3.70; grams, were added slowly over a period ofapproximately 6 hours at a rate of about 60 grams per hour .or slightlyless at a gram per minute. Whenever the temperature tended to rise past131 C. the reaction mass was cooled; if the temperature showed atendency to drop below l15 C.-'to 118 C. the reaction mass was heated.When all the glycide had been added the reaction mass was stirred forapproximately onehour longer at 135 'C., and then. was heated to atemperature below the decomposition point of glycide, for instance, 140(7., and held at this temperature for another hour. In this particularreaction there is less hazard than in usually the case insofar that theamount of glycide. added was comparatively small and it was addedslowly. Even so, such oxyalkylation could be conducted with extremecare. Other. catalysts; can. be employed such as caustic soda, orcaustic potash, but purely as a matter of convenience I have employedsodium methylate. The amount of catalyst can be increased but theobjectionis that more a1- kaline material must. be subsequently removedprior to esterification as described in Part 3, following, or thereaction may take place too rapidly or one might possibly polymerize theglycide itself rather than have it react with the; glycol et er.

PART 2- v Fora number of well known reasons equip.- ment, Whetherlaboratory size, semi-pilotplant size, pilot plant size, or large scalesize, is not as a rule designed for a particular alkylene oxide.Invariably and inevitably, however, or particularly in the case oflaboratory equipment and pilot plant size the design is such astou'seany of the customarily available alkylene oxides, i. e., ethyleneoxide, propylene oxide, butyl'ene oxide,

y d ep c lorohydrin, styrene oxide, etc. In

the subsequent description of the equipment it becomes obvious that itis adapted for oxyeth ylation as well as oxypropylation.

oxypropylations are conducted under, a wide variety of conditions, notonly in regard to presonce or absence. of, catalyst, and! the kind ofcatalyst, but also. in-regard to theitime of'reaction, temperature ofreaction; speed. of reaction, pressure during reaction, etc; For;instance, oxyalkylationsi can be. conducted at temperatures up toapproximately 200? C; with pressures in. about the same range up'to:.about 200: pounds per square inch. They can be conductedalsoattemperatures approximating the boiling point of water or slightly above,as for example to C. Under such circumstancesthe pressure will be lessthan 30 pounds per square inch unless some special procedure is employedas is sometimes the case, to wit, keeping an atmosphere of inert. gassuch as nitrogen. in the. vessel during the reaction. Suchlow-temperaturelow reaction rate oxypropylations have been describedvery completely inU. S. Patent No.'.2,448',664, to H. R. Fife. et alz,dated'September 7', 1948. Low temperatures, low pressurevoxypropylations are particularly desirablewh'ere the compound beingsubjected to oxypropylation contains one, two or three points ofreaction only, such as monohydric alcohols, glycols and triols;

Since low pressure low temperaturereaction speed oxypropylations requireconsiderable time, for instance, '1 to '7' days of 24 hourseach tocomplete the reaction'they are conducted as a rule whether on alaboratory scale, pilot plant scale, or large scale, so. as to operateautomatically. The priorfigure of. seven days applies especially tolarge-scale operations; -I havefused conventional equipment with twoadded-automatic features: *(a) a: solenoidcontrolled valve which shutsoff the propylene oxide in: event that the temperature gets. outside apredetermined and set range, for instance, 95 to 120 C., and (12)another solenoid valve which shuts cit the propylene oxide ("or for thatmatter ethylene oxide if it is being used)" if the'z 'pressure getsbeyond a predetermined'range, such as 25 .to 35 pounds. Otherwise, theequipment is substantially the same as is commonly employed for thispurpose where the pressure of reaction is higher, speed of reaction ishigher, and time of reaction is much shorter. In such. instances suchautomatic controls are. not necessarily used.

Thus, in preparing the various examples I have found it particularlyadvantageous to use laboratory equipment or pilot plant which isdesigned to permit continuous oxyalkylation'whether it be oxypropylationor oxyethylation. With certain obvious changes the equipment can be usedalso to permit oxyalkylation involving the use .of glycide where nopressure is involved except the vapor'pressure of a solvent, if any,which may have been used as a diluent.

As previously pointed outthe method of using propylene oxide is the sameas ethylene oxide.

This point is emphasized-only for the reason that the apparatus is sodesigned and constructed as to use either oxide. w

Th oxypropylation' procedure employed in the preparation of theoxyalkylated derivatives has been'uniformly-the same, particularly inlight of the fact that a continuous automatically-controlled proced-urew'asemployed. In this procetime the autoclave was a-'conventionalautoclave made of stainless steel'and' having acapacity of approximately15 gallons and a workingpressure of one thousand pounds gauge pressure.This pressure obviously is far beyond any requirement as far aspropylene oxide goes unless there is a reaction of explosiveviol'enceinvolved due to accident. The autoclave was equipped with thethermocouple for mechanical thermometer;

emptying outlet, pressure gauge, manual vent line; charge hole forinitial reactants; *atv least one connectionforintroducing the alkyleneoxide, such as propylene oxide or ethylene oxide, to the bottom of theautoclave;- along with suitable devices for both cooling and heatin -theautoclave, such as a cooling jacket; and, preferably, coils in additionthereto, with thej'acket so arranged that itis'suitable for heating withsteam or cooling with. water and further equipped with electricalheating devices." Such autoclaves are, of course, in essence small-scalereplicas of the usual conventional autoclaveiused in oxyalkylationprocedures. In some instancesinexploratory preparations an autoclavehaving a smaller capacity, for instance, approximately 3 liters in onecase and about 1% gallons in another case,

was used.

Continuous operation, or. substantially continuous operation, wasachieved by the use of a separate container to hold the alkylene oxidebeing employed, particularly propylene oxide. In conjunction with thesmaller autoclaves, the container consists essentially of a laboratorybomb having a capacity of about one-half gallon, or somewhat in excessthereof. In some instances a larger bomb was used, to wit, one having acapacity of about one gallon. This bomb was equipped, also, with aninlet for charging, and an educator tube going to the bottom of thecontainer so as to permit discharging of. alkylene oxide inlthe' liquidphase to the autoclave. A bomb having a capacity of about 60 pounds wasused in connection with the l5.-gallon autoclave. Cther conventionalequipment consists, of course, of the rupturedisc, pressure gauge, sightfeed glass, thermometer connectionfor nitrogen for pressuring bomb, etc.The bomb. was placed on a scale during use. The connections between thebomb and the autoclave were flexible stainless steel hose or tubing sothat continuous weighings could be made without breaking or making anyconnections. This applies also to.the nitrogen line, which was used topressure the bomb reservoir. To the extent that it was required; anyother usual conventional procedure or addition which provided greatersafety was used, of course, such as safety glass protective screens,etc.

Attention is directed again to what has been said previously in regardto automatic controls which shut off the propylene oxide ineventtemperature of reaction passes out of the predetermined range or ifpressure in the autoclave passes out of predetermined range.

With this particular'arrangement practically all oxypropylationsbecomeuniform inthat the reaction temperature'was held within a few degrees ofany selected point, for instance, if 105 C; was selectedas the operatingtemperature the maximum point would. be at the most 110C. or 112 C.-,and the lower point would'be 95 or possibly 98 C. Similarly, thepressure was held at approximately 30 pounds within a 5-poundvariationone way or the other, but might drop to practically zero, especiallywhere no solvent such as xylene is employed. The speed of reaction wascomparatively slow under such conditions as compared with oxyalkylationsat 200 C. Numerous reactions were conducted in which the time variedfrom one day (24 hours) up to three days (72 hours), for completion ofthe final member of 8 aseries. In some instances the reaction may takeplace in considerably less time, i; e., 24 hours or less, as faras apartial oxypropylation is 0011? cerned.'

The/minimum time recorded was a 4-hour period.- Reactions indicatedasbeing complete.

in four hours for thereabouts may have been complete in a lesser periodof time in light of the automatic equipment used. This applies also tolargerautoclaves where the reactions were complete in 9 to 12 hours. Intheaddition of propylene oxide, in' the autoclave'equip'ment as far aspossible the valves were set so all the propylene oxide was fed in at arate'sothe predetermined amount reacted in the "first twothirds-of theselected periods; for instance, ifthe selected period'was 3' hours" therate was set so the oxide could be'fed in in two hours or less. Thismeant that if the reactionwas interrupted automatically for a period oftime for "the pressure to drop, or the temperature to drop, thepredetermined amount of oxide would still be added in most instanceswell within the predetermined time period. In one experiment theaddition of oxide was made over a comparatively long period, i. e., 10hours. In such instances, of coursfirthe reaction could be speeded up toquite a marked degree. L

When operating at acomparatively high temperature, for. instance,between 150 to200 C., an unreacted .alkylene oxide such as propyleneoxide, makes its presence felt in theincrease in pressure or theconsistency of a higher pressure. However, at a low enough temperatureit may happen that the propylene oxide goes in as a liquid. If so, andif it remains unreacted there is, of course, an inherent danger andappropriate steps must-be taken to safeguard against this possibility;'if need be a samplea'must be withdrawn and examined for unreactedpropylene oxide. One obvious procedure, of course, is to oxypropylate ata. modestly higher temperature, for instance, at to C. Unreacted oxideaffects determination of the acetyl 'or hydroxyl value of thehydroxylated compound obtained.

The higher'the molecular Weight of the compound, i. e., towards thelatter stages of reaction, the longer the time required to add a'givenamount of oxide. One possible explanation is that the molecule, beinglarger, the opportunity for random reaction is decreased. Inversely, thelower the molecular weight the faster the reaction takes place. For thisreason, sometimes at least,increasing the concentration of the catalystdoes not appreciably speed up the reaction, particularly when theproduct subjected to oxyalkylation has a comparatively high molecularweight. However, as has "been pointed out previously, operating at a lowpressure and a low temperature even in large scale operations as much asa week or ten days time may lapse to obtain some of theQhigher molecularweightderivatives from monohydric. or dihydric materials.

In a number of operations the counterbalance scaleor'dial'scale holdingthe propylene oxide bomb was so set that when the predetermined amountof propylene oxide had passed into the reaction the scale movementthrougha time .operating device was set foreither one to two hours sothat reaction continued for 1 to 2 hours after the final addition of thelast propylene oxide and thereafter the operation was shut down. Thisparticular device is particularlysuitable for use on larger equipmentthan laboratory size 'autoclaves, to wit, onsemi-pilot plant or pilotplant' size, as well as on'large scale size. *rmsnmr stirring periodisnintende'di to avoid the presence of unreac'ted oxide.

Imthis sort of operation, :of course, the temperaturerange was:controlled automatically by :either use of .co'olingwatensteam, orelectrical heat, :so :as to raise. or. lower the temperature. ,The.pressuringiof the propylene oxide into the reaction vessel was alsoautomatic insofar that the feed stream was set for a slow continuous runwhich was shut off .in case .the pressure passed a predetermined pointas previously set out. All the points of design, construction, etc.,

were conventional including-the gases, check valves and entireequipmentj As far asfI. am

if) the remainder. subjected. to further oxypropylation as described inExample 2, immediately following... p.-

EmampZe Zb far as temperature and pressure were concerned aware at leasttwo firms, and possibly three v specialize in autoclave equipment suchas ,Ihave employed in the laboratory, and are prepared to furnishequipment of this same kind. Similarly pilot plant equipment isavailable. This point is simply made as a precaution in the direction ofsafety. Oxyalkylations, particularly involving ethylene oxide, glycide,propylene oxide, etc., should .notbe conducted except, inv equipmentspeciiicallydesig'nedjfor the purpose;

propylation was very short, with manual con way the autoclave washandled.

145 grains of the' di'hydroxylated compound previouslydescribed' werecharged into the autoclave along'with 15 grams of causticsoda. It is tobe noted that the sodium methylateused in the glycide reactionwas-permitted to remain in the reaction mass.- This meant that the--concentrationof catalyst was slightly higher than indi'cated by theamount- 0f caustic soda. '-Ihe react'ionpot was flushed out withnitrogen; the autoclave was sealed and *the automatic devicesadjfistedior injecting-675 grams of propylene oxide in approximately a2-hour "period. The pressure regulator was set for a maximum of poundsper square inch; -'-I'-his meant that the bulk of the reaction couldtake place, and probably didatake" placeat a comparatively-lowerpressure This comparatively lower pressure was the xesultLof thefact-that, itleast in part, considerable catalyst was present, Thepropylene oxide. was :added at approximately a rate of about 450 gramsper hour in this instance. As previously: stated, the time required toaddall the oxide :was 2 hours )butj this 1 included a shortstirring-period at the end of the reaction when no .a'ctualoxide'wasentering the apparatus; More important the selected maximumtemperature'range was -'-l10 0.- =(moderatelyabove'the boilingpointo'f'water). The initial introduction ot-propylene oxide was not starteduntil the :heating devices had raised the temperature just a trifleabove 1'00 -C'. {When the reaction was complete approximately one-halfof 'the reaction mass "was withdrawn as a sample and trol. Needless tosay, it wasimxfiaterial which were substantially the same as "in"Example1b, preceding. The time required 'to'add the oxide was a little bitlonger, ,that is, 2 -hours, notwithstanding the fact that the amount ofoxide added was considerably less. The rate of addition of the oxide wasabout 200: grams per hour. At the completion offthis stage oroxypropylation part of the sample was withdrawn and. the

remainder subjected to furtheroxypropylation as described in Example3b,- immediately following.

Example 3b 411 grams of the reaction mass identified .as Example 3b,=preoeding, and; equivalent to 3'7 grams of the original,dihydroxymaterial, 370 grams of oxide, andgl grams of catalyst, weresubjected to further oxypropylation with 198 grams of propyleneoxide.This was reacted without the use-of additional catalyst. The-conditions;of reaction as far as temperature and pressure were concerned were thesame as in Example 2b, preceding, except that the maximum temperaturewas somewhat higher, i. e., C., instead of 110 -C. Thetime required toadd the oxide was considerably longer than previously, .to.

wit, 5 hours. The addition was made at the rateof about-40 grams perhour. At the,co mpleztl'OIl of the reaction part of the reaction masswaswithdrawn and the remainder subjected to the final oxypropylation stepas described in Example 411-, immediately following.

Ercdmple4b. I I

207 grams of the reaction mass identified as ExampleBb, preceding,equivalent to 13 grams of the original-dihydroxylated material, 193grams of oxide, and 'onelgramoftcatalyst, were subjected to furtheroxypropylation with 64 grams; of pro- 'pylene oxide. This was'reactedwithout the use of additional catalyst. Themaximum pressure was the sameas in previousexamples, i.'e., 35 pounds. Thetemperatu-re in thisinstance was somewhat higher than in any of the previous examples'towit, C. "Ihe'tim'e'required to add the oxide was somewhat longernotwithstanding the smaller amount, i. e.,'6 hours. It was added at therate of about 12 grams per hour. The aboveseries was duplicated anum-berof times to give larger amounts for subsequent esterifications.

In :the hereto attached-tables it will be noted that this series showstheoretical molecular weights varying from 1,000 to-4,0.00, and hydroxylmolecular weights varying from a little less than 850 to a little lessthan .1400. In another series of experiments I proceeded further bythree additional steps; ;at a molecular weight corresponding to 5,000theoretical,- "the fhyiiioxyl molecu lar weight was ,approximiatelymfib; at-6',0001theoretical molecular weight"-the hydroxyl molecularsome addedv information as to molecular weight and as to solubility ofthe reaction product in 12 particularly. dicarboxy acids suchas adipicacid. phthalic acid, or anhydride, succinic; acids, diglycollic acid,sebacicacid, azelaicraidgaconitic acid, maleic acid. or anhydrida;citraconicacid or anhydride, maleic acid Ol'gfiflhYdIidB adducts asobtained by. the Diels-Alder'reaction fromproducts'su'ch as maleicanhydride, and .cyclopentadiene. Such acids should be heat stable sothey are not decomposed during esterification.

watenxylene and kerosene. They may'contain as many as 36-carbon atomsTABLE 1 I Composition Before Composition at End M W Max I e by Max.Pres, Tk'ne I H. or Oxide cm- Theo. 11.0. Oxide Catag is- 95 Hrs. i Amt,Amt; lyst, M01. Amt, Amt, lyst, i3 j grs. grs. grs. Wt. grs. grs. grs.

...145, 1a 996 145 675 '840 11c "as j 73 as! 7 1,955 73 v739 7 1, 264 noas. 2%-

37 370 4 2,875 37 568 4 1, sec 115 35 45% 13 19a 1 3,655 13 257 1 1, 365125 '35 V e The hydroxylated compound is the glycerol ether of normalhexyl alcohol.

Example lb was emulsifiable in water, soluble in xylene and insoluble inkerosene; Examples 2b, 3b and 4b were all insoluble in water, butsoluble in both xylene and kerosene;

The final product; i. e., at the end of the oxypropylation step, was asomewhat viscous pale amber-colored fluid which was water-insoluble.This is characteristic of all various end products obtained in thisseries. These products were, of course, slightly alkaline due to theresidual caustic soda employed. This would also be the case if sodiummethylate were used as a catalyst.

- Speaking of'insolubility in water or solubility in-kerosene suchsolubility test can be made simply by shaking-small amounts of thematerials in a test tube with water, for instance, using 1% to-5%approximately based on'the amount of water present. I

Needless to say, there is no complete conversion of propylene oxide intothe desired-hydroxylated compounds. This is indicated by the fact thatthe theoretical molecular weight based on a statistical average isgreater than the molecular weight calculated by usual methods on basisof acetyl 'or hydroxyl value. Actually, there is no completelysatisfactory method for determining molecular weights of these types ofcompounds with a high'degree of accuracy when the molecular weightsexceed 2,000. In some instances the acetyl value or hydroxyl valueserves as satisfactorily as an index to the molecular weight as anyother procedure, subject to the above limitations, and especially in thehigher molecular weight range. If any difficulty is encountered in themanufacture of the esters as described in Part 3 the stoichiometricalamount of acid or acid compound should be taken which corresponds to theindicated acetyl or hydroxyl value. This matter has been discussed inthe literature and is a matter of common knowledge and requires nofurther elaboration. In fact, it is illustrated by some of the examplesappearing in the patent previously mentioned.

PART 3 As previously pointed out the present invention is concerned withacidic esters obtained from the propylated derivatives described in Part2, immediately preceding, and polycarboxy acids,

as, for ex'ampl, the acids obtained by dimeriza- 7 tion of unsaturatedfatty acids, unsaturated monocarboxy fattyacids, or unsaturatedmonocarboxy acids having 18' carbon atoms. Reference to the acidvinthehereto appended claims obviously includes the anhydrides or anyother obviousequivalents. MY, Preference, however, is to use polycarboxyacids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and glycols or other hydroxylated compounds is wellknown. Needless to say, various ,compoundsmay be used such as the lowmolal ester, the anhydride, the .acyl chloride, etc. However, forpurpose of economy it customarytouse either the acid or the anhydride,--A conventional procedure is employed. On a laboratory scale one canemploy a resin :pot of the kind described in U. S. Patent No. 2,499,370,dated March '7, 1950 to De Groote and Keiser, and-particularly with onemore opening to permit the use of a porous spreader if hydrochloric acidgas is to be used as a catalyst. Such device oriabsorption spreaderconsists of minute Alundumthimbles which are connected to a glass tube.One can add a sulfonic acid such as para-toluene sulfonic acidas acatalyst. There is some objection to this because insome instancesthere, is some evidence that this acid catalyst tends to decompose orrearrange heat oxypropylatedi compounds, and par,- ticularly likely tovdo so if the esterification temperature is too high. In: the caseofpolycarboxy acids such as =diglycol1ic acid, which is strongly acidicthere is no need to add any catalyst. The use of hydrochloric gas hasone advantage over paratoluene sulfonic acid and that is that at the endof the reaction it can be removed by flushing out with nitrogen, whereasthere is no reasonably convenient means available of removing theparatoluene sulfonic acidor other sulfonic' acid'employed. If vhydrochloricacid is employed one need only pass the gas through at anexceedingly slow rate so as to keep the reaction mass acidic. Only atrace of acid need be present. 1 I: have employed hydrochloric acid gasor the aqueous 'acid itself to eliminate the initial-basic'material. Mypreference, however. is to use no catalyst whatsoever andtoinsure'complete dryness of the diol as The products obtained in Part2preceding may contain a basic catalyst. As a general procedure I haveadded an amount ofhalf-concentrated hydrochloric acid considerably inexcess of what is required to neutralize the residual catalyst.

stand overnight. It is then filtered and refluxed with the xylenepresent until the watercan be separated in a phase-separating trap.- Assoon.

chloride during the reflux stage needless to say a second filtration maybe required. In any'event 14 as water of solution or the equivalent.Ordinarily this refluxing temperature is apt to be in the neighborhoodof 130. to possibly 150 C.

. When all this water or moisture has been removed I-a1so Withdrawapproximately 20 grams or a little less benzene and then add therequired amount of the carboxy reactant and also about The mixture isshaken thoroughly and allowed to,

150 grams of a high boiling aromatic petroleum solvent. ll l'iesesolvents are sold by various oil refineries and," as far as solventefifect'ajct as if they L were almost completely aromatic in: character.Typical distillation data in the particular type I This preliminary stepcan the neutral or slightly acidic solution of the oxy- V have employedand found-very satisfactory is the following:

' I. B. P., 142 C. 50 ml.,:242 C. 5 ml., 200 C. -'55 ml., 244 C. ml 209C 60 ml., 248 C. ml., 215 C. 65 ml., 252 C. ml., 216 C. 70 ml., 252 C.ml., 220 C. '75 ml., 260 C. ml., 225C. 80 ml., 264 C. ml., 230 C. 85ml., 270 C. 'm1., 234 C. 90 ml., 280 C.

if on produpesia half-ester from a'nianhydride such [as phtl aliclafihyd'ride',Tno Water is eliminatedi However, if it is obtainedjfromdiglycollic acid, for example, .WateriseIiminatedJ All such prte' arest; are conventional and' "have been so thoroughly. described inthe'lite'ra'ture' that fur: ther consideration "will. be limited to afew examples and acomprehenfsivetable. p

' Other procedures for eliminating the basic residual catalyst, if any,canbe employed. For

example, the oxyallrylation'can be conducted in absence of ,asolventorthe solvent removed after oxypropylation Such oxypropylation endproduct-canthen beacidified with just enough con; centrated hydrochloricacid to just neutralize the residual basic catalyst. ,{I'o this productone-can then add asmall amount. .of anhydrous sodium sulfate (suflicientin quantity to take up any water thatis present) and then subject themass to centrifugal force so as to eliminate the sodium sulfate andprobably the sodium chloride formed. The clear somewhat viscousstraw-colored amber liquid so obtained maycontain a small amount ofsodium sulfate orsodium chloride but, in any event, perfectly acceptablefor esterification in the manner described... a

It is to be pointed out that the products here described. arenot,polyesters in.- the sense that there is a plurality of both diolradicals and acid radicals; the product is characterized by having onlyone diol radical. J In some instances and, in fact, in manyinstances Ihave found that in spite of the dehydration methods employed above thata mere trace of water still comes through and that this mere trace ofwater certainly interferes with the acetyl or hydroxyl valuedetermination, at least when a number of conventional procedures areused and may retard-esterification, particularly where there is 'nosulfonic acid or hydrochloric acid present as a catalyst Therefore, Ihave preferred to use thefollowing procedure: Ihave employedabout200grams of'the' diol as described inPart 2, preceding; Irhave added about60 grams of benzene, and then refluxed this mixture in'the 45ml, 237 C.95 ml., 307 C.

After this material is addedLrefluXIng is continued and, of. course,'fisat a'ihigh temperature, to wit, about 160 to 170 C. If the carboxyreactant is an anhydrideineedless to say no water of reaction appears;if the carboxy reactant is an acid, water of reaction should appear andshould be eliminated at the above reaction temperature. If i it is noteliminated I simply separate out another 10 or 20 cc. of benzene bymeans of the phase-separating trap and thus raise the temperature to 180or 190 0., or even to 200 C., if need be. Myflpreference is not to goabove C- I -21 1 The use cfsuclisolvent' i extremely satisfac toryprovided one does not attempt to remove the solvent subsequently exceptby vacuum dist'ill'ation and provided-thereis' no objection to a littleresidu'eif "Actually.when-these materials are used for a purposesuchasdemuIsificatiOn'the solvent mightjust as we'll be allowed toremain. If the solvent is to be removedfbydistillation, and particularlyvacuum distillation, then the high boilingarom'atic petroleumsolventmight well be replaced'by somemor' expensive solvent, such :as decalinor an alkylated decalin'which has a rather definite or close rangeboiling point. The reglass resin -pot :using aphase-separ'ating trapuntil the benzene carried out all the water present ventional procedureand requires no elaboration.

In the appended tableS'olvent #7-3, which appears in numerous instances,is amixture of 7 volumes of the aromatic petroleumsolvent previouslydescribed and 3, volumes of benzene. Referenceto Solvent #Tmeans theparticular petroleum solvent previously described in detail. This wasused, or a similar mixture, in the manner previously described. A largenumber of the exam les ind ca e em loy decalin we r peated using thi-mixture-and particularly with the preliminary step of removing :allthewater. If one does not intend to remove the solvent my preference to.use the petroleum solvent-benzene mixture although obviously any of theother mixtures, such as; decalinand xylene, can be employed. c. The.data'included inithe subsequent tables, 1. e.. Tables 2.,-iand.-. 3;....are-sselfexplanatory, and very complete and it is-believedno furtherelaboration isnecessary:

'.- ;TABLE.-2'

'Ex. 10 0195. Them T1150. Actual (M01. wt. Amt. 01 1 3? i g g gig; M. W.Hydroxyl B2335 Polycarbox'y Rcactant carboxy E515; ompd. 11.0. ValueH.V. (grs) ags;

15" 996 1, 50 134 340 174 Diglycolicrkcidun. 55.5 :25 1,955 57.5- "99.01,254 232 --4s.7 2.35; 2,875.1." 39.2 v31.0. 1,390 135 do 30.5 ,40 3,05530.3 32.4 7 1,305 103 .-.do .7 21.3 "35 2, s75 39.2- v 310 1,390 133Phthalic Auliydride 40.3 .35 2,375. 139.2 1 31.0 1,390 138 MaleicAnhydride" 20.7 35 375. 39.2 81.0 1,390 193 Succinic Anhydride- 27.2 -153,055 30.21 32.4 1,305 108 PhthelicAnhyclride; 24.0 45 3, 055 30.9 82.41, 355 s MaleicAnhydride-.- 10.0 45 3, 555 30.5 52.4 1,305 108 Succinic111111 01105. 10.3 995 1,100 134. 510 174 PhthalicAnhydride. 01.5 15 9901,100 134 840 174 Maleichnhydridan 41.4 15 990 1,150 134 840 V 174SuccinicAnhydride. 42.2 1,955 57.5 39.0 1, 204 232 PhthalicAnhydride.51.0 25 1, 955 57.5 39.0 1, 254 232 MaleicAnhydricle, 35.7 25 1,955 57.539.0 1,204 232 Succinic Anhydride. 5.4

TABLE 3 stances an attempt to. react the stoichiometric amount ofa-polycarboxy acid with the oxypro- I Esierifr Time of 1 tedderivatiresults in an excess f the car- Amt. Water DY a V9 0 i-ggi g y e 2331Em? 33% boxylated reactant for the reason that apparg 25 ently underconditions of reaction less reactive hydroxyl radicals are present thanindicated by 226 152 4% the hydroxyl value. Under such circumstances 274154 0 7.0 222 153 4% there is simply a residue of the carboxyhc re- }:3g actant which canbe removed by filtration or, it 142, 1 11:11::desired,.th'e esterification procedure can be rel2; peated using anappropriately reduced ratio or 83 1 3 carboxylic reactant. j 183 153Even the determination of the hydroxyl value 220- 142 144 andconventional procedure leaves much to be desired due either to thecogeneric-materials pre- 214 2 viously referred to-, jor for thatmatter, the presence of any inorganic salts or' propyleneoxide.

The procedure iorfmanufacturing the esters has been illustrated bypreceding examples. If for any reason reaction does not take place in amanner. ;that. is acceptable, attention should be directed' to theffollowingdetails! (a) Recheck the 'hydroxyl or, 'acetyl value of theoxypropylated glycerol anduis e fi stoichiometrically equivalentamount'ofiacidf; ",(b) "the reaction does not proceed with reasonablespeed either raise the temperature indicated or else extend the periodof time upto 12 or 16 hours'if need be; (c) if necessary, use /2% ofparatoluene sulfonic acid or someotheracid as a catalyst; (d) if theesterification does not produce a clear product a check should 55111335to'see if an inorganic salt such as sodium chloride or sodium sulfate isnot precipitating ,out. Such salt should be eliminated, at least forexploration experimentation, and can be removed by filtering. Everythingalso being equal as the size of the molecule increases and the reactivehydroxyl'radical represents a smaller fraction of the entire moleculeand thus more difficulty is involved in obtaining completeesterification. I

Even under the most carefully controlled conditions of oxypropylationinvolving comparatively low temperatures and long time of reaction thereare formed certain compounds whose composition is still obscure. ISuchside reaction products can contribute a substantial proportion of thefinal cogeneric reaction mixture. Various suggestions havebeen made asto the nature of these compounds, such as being cyclic polymers ofpropylene oxide, dehydration products with the appearanceof avinylradicahor isomers of Obviously this oxide should be eliminated.

The solvent employed, if any, can be removed from the finished esterbydistillation and particularly vacuum distillation. The final products orliquids are generally light straw to light amberf inc'olor,-'andshowmoderate viscosity. They can be bleached with bleaching clays, filtering5115.15,; an'd'the like. However, for the purpose or demulsification orthe like color is not a factor and decolorization is not justified.

In the above linstances I have permitted the solvents to remain presentin the final reaction mass. Inother instances I have followed the sameprocedure using, decalin or a mixture of decalin or benzene in the samemanner and ultim'ately removed all the solvents by vacuum distillation.Appearances of the final products are much the same as the diols beforeesterification and in some instances were somewhat darker in color andhad areddish cast and perhaps somewhat moreviscous.

' PART 4 Previous referencehas been made to thefact that diols such aspolypropyleneglycol of approximately 2,000 molecular weight, forexample, have been esterified with dicarboxy acids and employed asdemulsifying agents. On first examination the difference between theherein described products and such comparable products appears to berather insignificant. In fact, the difference is such that, it fails toexplain the fact that compounds of the kind herein described may be, andfrequently are, 10%, 15% or 20% better on a quantitative basis than thesimpler compound previously described, and demulsiiy faster and givecleaner oil in many instances. The method-of making such comparativetests 1? has been described in a booklet entitled TreatingOil FieldEmulsion, used in the Vocational Training Courses,Petroleum IndustrySeries, of

the American Petroleum Institute.

The difference, of course, does not reside in the carboxy acid but inthe diol. Momentarily an eiiort will be made to emphasize certain thingsin regard to the structure of a polypropylene glycol, such aspolypropylene glycol of a 2000 molecular weight. Propylene glycol has aprimary alcohol radical and a secondary alcohol radical. In; this sensethe building unit which forms polypropylene glycols is not symmetrical.Obviously, then, polypropylene glycols can be obtained] at leasttheoretically, in which two secondary alcohol groups are united or asecondary alcohol group is united to a primary alcohol group,'etherization being involved, of course, in each instance.

Usually no eiiort is made to differentiate between oxypropylation takingplace, for example, at the primary alcohol unit radical or the secondaryalcohol radical. Actually, when such products are obtained, such as ahigh molal polypropylene glycol or the products obtained in the mannerherein described one does not obtain a single derivative such asHO(RO)nH-in which n has one and only one value," for instance, 14, l5 orl6 or the like. Rather, one obtains a cogeneric mixture of closelyrelated or touching homologues. These materials invariably have highmolecular weights and cannot be separated from one another by any knownprocedure without decomposition. The properties of such mix turerepresent the contribution of the various individual members of themixture. On a statistical basis, of C0llIS,"TL can be appropriatelyspecified. For practical purposes one need only consider theoxypropylation of a monohydric alcohol because in essence this issubstantially the mechanism involved. Even in such instances where oneis concerned with a monohydric reactant one cannot draw a single formulaand say that by following such procedure one can readily obtain 80% or90% or 100% of such compound, However, in the case of at leastmonohydric initial reactants one can readily draw the formulas of alarge number of compounds which appear in some of the probable mixturesor can be prepared as components and mixtures which are manufacturedconventionally.

j 'Ho'wever, momentarily referring again to a monohydric initialreactant'it is obvious that if one selects any such simple hydroxylatedcompound and subjects such compound to oxyalkylation, such asoxyethylation, or oxypropylation, it becomes obvious that one is reallyproducing a polymer of the alkylene oxides except for the terminalgroup. This is particularly true where the amount of oxide added iscomparatively large, for instance, 10,20, 30,40, or 50 units. If suchcompound is subjected to oxyethylation so as to introduce units ofethylene oxide, it is well known "that 'one doesnot obtain a singleconstituent 'which, f0r the sake of convenience, may be indicated asRO(C2H40)3oOI-I. Instead, one obtains a cogeneric mixture of closelyrelated homologues, in which the formula may be shown as the following,RO(C2H4O') 1H, wherein n, as far as the statistical average goes, is 30,but the individual members present in significant amount may vary frominstances where n has avalue of 25, and perhaps less, to a point where nmay represent or more. as stated, a cogeneric closely related series ofSuch mixture is,

touching homologous compounds. Considerable investigation has been madein regard to the distribution curves for linear polymers. Attention isdirectedto the article entitled Fundamental principles of condensationpolymerization, by Flory, which appeared in Chemical Reviews, volume 39,No. 1, page 137. v I

Unfortunately,-as has been pointed'out by Flory and other investigators,there is no satisfactory method, based on either experimental ormathematical examination, of indicating the exact proportion of thevarious membersof touching homologous series which appear in cogenericcondensation products of the kind described This means that from thepractical standpoint, i. e., the ability to describe how to make theproduct under consideration and how to repeat such production time aftertime without difficulty, it is necessary to resort to some other methodof description, or else consider. the value of n, in formulas such asthose whichhave appeared previously and whichappear in the claims, asrepresenting both individual constituents in which n has a singledefinite value,

and also with the understanding that n represents the averagestatistical value based on the assumption of completeness'of reaction.

This may be illustrated as follows: Assume that in any particularexample'the molal ratio of the propylene oxide to the diol is 15 to 1.Actually, one obtains products in which n probably varies from 10 to 20,perhaps even further. The average value, however, is 15, assuming, aspreviously stated, that the reaction is complete. The prod-' uctdescribedby the formula is best described also in terms of method ofmanufacture.

However," inthe'insta'nt situation it becomes obvious that if anordinary high molal propyleneglycol is compared'to strings of Whitebeads of various lengths,the diols herein employed as in-- termediatesare characterizjed'by the'presence of a black bead, i. e.,a'radical-'whichc'orresponds to the glycerol ether-of a hexyl alcohol,particularly' normal hexanol as previously described, i.e., the radical.

Furthermore, it becomes obvious now that one has a nonsymmetricalradical in the majority of cases for reason that in that cogeneric"mixture going back to the original formula n and n are usually notequal. For instance, if one introduces 15 moles of propylene oxide, 12.and n could not be equal, insofar that the nearest approach to equalityis where the value of n is '7 and n is '8.- However, even in the case ofanfeven number such as 20, 30, 40"or'50,"it'is also obvious that n and11. will not be equalin light of what has been said previously. Bothsides of the molecule are not going to grow with equal rap idity, i. e.,to the same size. Thus the diol herein employed in differentiated frompolypropylene diol 2000, for example, in that (a) it carries aheterogeneous unit, i. e., a unit other than a propylene glycol orpropylene oxide unit, (b) such unit is 01f center, and (c) theeffect ofthat unit, of course, must have some effect in the range with which thelinear-molecules can be drawn together by hydrogen binding or van derWalls forces, or whatever else maybe involved.

What has been said previously can be' emphasizedin the following manner.It has been pointed'out previously that in the last formula immediatelypreceding, n or n could be zero. Under the conditions of manufacture asdescribed in Part 2 it is extremely unlikely that 'n is ever zero.However, such compounds can be prepared readily with comparativelylittle difficulty by resorting to a blocking effect or reaction. Forinstance, if the glycerol ether as previously described is esterifiedwith a low molal acid'such as acetic acid mole fpr mole and such productsubjected'to oxyalkylation using a catalyst, such as sodium methylateand guarding against the presence of any water, it becomes evident thatall the propylene oxide introduced, for instance to 80 molecule perpolyhydric alcohol necessarily must enter at one side only. If suchproduct is then saponified so as to decompose theacetic acid ester andthen acidified so as to libera'te the water-soluble acetic acid and thewater-insoluble diol a separation can be, made and such 'diol thensubjected to esterification as described in Part 3, preceding. Suchesters, of course, actually represent products where either n or n iszero. Also intermediate procedures can be employed, 'i. e., followingthe same esterification step after partial oxypropylation. For in-'stance, one might oxypropylate with one-half the ultimate amount ofpropylene oxide to be used and then stop the reaction. One could thenconvert this partial oxypropylated intermediate into .an ester byreaction of one mole of acetic acid with one mole of diol. This estercould then be oxypropylated with all the remaining propylene oxide. Thefinal product so obtained could be saponified and acidified so as toeliminate the water-soluble acetic acid and free the obviouslyunsymmetrical diol which, incidentally, should also be kerosene-soluble.I

- i From a practical standpoint I have found no advantage ingoing tothis extra step but it does emphasize the difierence in structurebetween the herein described diols employed as intermediates and highmolal polypropylene glycol, such as polypropylene glycol 2000.

The most significant fact in this connection is the following. Theclaims hereto attached are directed to a very specific compound, i. e.,one derived by the oxypropylation of the glycerol ether of -hexylalcohol. I-have prepared a number of other dihydric compounds which weresimilar, such as compounds obtained by the treatment of glycol etherswith a mole of glycide. The dihydroxy compounds obtained were thentreated with polycarboxy acids in the same manner as herein described inconnection with the glycol ether of normal hexanol or the like. Amongsuch glycol ethers employed were the following: Monomethyl ether;ethylene glycol ethylbutyl ether; ethylene glycol monophenyl ether;ethylene-glycol monobenzylether; diethylene glycol monomethyl ether;diethyleneglycol monoethyl ether; and diethylene glycol mono butylether.

I have taken each and every one of these glycol ethers and, as a matterof fact, a large number of ethers, subjected them to reactionwithglycide and then oxypropylated the compounds and esterified them inthe manner described in the instant application. I have tested all theseproducts for demulsification and, at least to date I have not foundanother analogous compound equally effective for demulsification andalso for certain other applications in v j 20 Y which surface activityis involved. At the moment, based on this knowledge, this particularcompound appears unique for reasons not understood.

PART 5 Conventional demulsifying agents employed in the treatment of oilfield emulsions are used as such, or after dilution with any suitablesolvent, such as water, petroleum hydrocarbons, such as benzene,toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols,particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol,denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octylvalcohol, etc., may be employed as diluents. such as pine oil, carbontetrachloride, sulfur dioxide extract obtained in the refining ofpetroleum, etc., may be employed as diluents. Similarly, the material ormaterials employed as the demulsifying agent of my process may beadmixed with one or more of the solvents customarily used in connectionwith conventional demulsifying agents. 7, Moreover, said material ormaterials may be used alone or in admixture with other suitablewell-known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used inawater-soluble form, or in an oil-soluble form, or in a form exhibitingboth 011- and water-solubility. Sometimes they may be used in a formwhich exhibits relatively limited oil-solubility. However, since suchreagents are frequently used in a ratio of l to 10,000 or 1 to 20,000 or1 to 30,000, or even 1 to 40,000, or 1 to 50,000 as in desaltingpractice, such an apparent insolubility in oil and water is notsignificant because said reagents undoubtedly have solubility withinsuch concentrations. This same fact is true in regard to the material ormaterials employed as the demulsifyingagent of my process.

In practicing my process for resolving petroleum emulsions ofthe'water-in-oil type,'a treating agent or demulsifying agent of thekind being used alone or in combination with other demulsifyingprocedure, such as the electrical dehydration process.

'One type of procedure is to accumulate a volume of emulsified oil in atank and conduct a batch treatment type of demulsification procedure torecover clean oil. In this procedure the emulsion is admixed with thedemulsifler, for example by agitating the tank of emulsion andslowlydripping demulsifier into the emulsion. In some cases mixing is achievedby heating the emulsion while dripping in the demulsifiendepending uponthe convection currents in the emulsion to produce satisfactoryadmixture. In a third modification of this type of treatment, acirculating pump withdraws emulsion from, e. g., the bottom of the tank,and reintroduces it into the top of the tank, the demulsifier beingadded, for example, at the suction'side of said circulating pump.

In a second type of treating procedure, the demulsifier is introducedinto the well fluids at the well-head or at some point between thewellhead and the final oil storage tank, by-means Of an adjustableproportioning mechanism or Miscellaneous solvents proportioning pump.Ordinarily the flow of fluids through the subsequent lines and fittingssuifices to produce the desired degree of mixing of demulsifier andemulsion, although in some instances additional mixing devices may beintroduced into the flow system. In this general procedure, the systemmay include various mechanical devices for withdrawing free water,separating entrained water, or accomplishing quiescent settling of thechemicalized emulsion. Heating devices may likewise be incorporated inany of the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsionis to introduce the demulsifier either periodically or continuously indiluted or undiluted form into the well and to allow it to come to thesurface with the well fluids, and then to fiow the chemicalized emulsionthrough any desirable surface equipment, such as employed in the othertreating procedures. This particular type of application is decidedlyuseful when the demulsifier is used in connection with acidification ofcalcareous oil-bearing strata, especially if suspended in or dissolvedin the acid employed for acidification. 'In all cases, it will beapparent from the foregoing description, the broad process consistssimply in introducing a relatively small proportion of demulsifier intoa relatively large proportion of emulsion, admixing the chemical andemulsion either through natural flow or through special apparatus, withor without the application of heat, and allowing the mixture to standquiescent until the undesirable water content of the emulsion separatesand settles from the mass.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted orundiluted) is placed at the well-head where the efiluent liquid leavethe well.

This reservoir or container, which may vary from well. Such chemicalizedfluids pass through the fiowline into a settling tank; The settling tankconsists of atank of any convenient size, for instance, one which willhold amounts of fluid produced in 4 to 24 hours (500 barrels to 2000barrels capacity), and in which there is a perpendicular conduit fromthe top of the tank to almost'the very bottom so as to permit theincoming fluids to pass from the top of the settling tank to the bottom,so that such incoming fluids do not disturb stratification which takesplace during the course of demulsification. The settling tank has twooutlets, on being below the water level to drain 01f the water resultingfrom demulsification or accompanying the emulsion as free water, theother being an oil outlet at the top to permit passage of dehydrated oilto a second tank, being a storage tank, which holds pipeline ordehydrated oil. If desired, the conduit or pipe which serves to carrythe fluids from the well to the settling tank may include a section ofpipe with baflles to serve as a mixer, to insure thorough distributionof the demulsifier throughout the fluids, or a heater for raising thetemperature of the fluids to some convenient temperature, for instance,120 to 160 F., or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as tofeed a comparatively large ratio of demulsifier, for instance, 115,000.As soon as a complete break or satisfactory demulsification is obtained,the pump is regulated until experience showsthat the amountof demulsifier being added isjust sufficient to produce clean or dehydratedoil. The amountbeing fed at such stage is usually 1:10,000, 1:15,000, 1:20,000, or the like.

In many instances the oxyalkylated products herein specified asdemulsifierscan be conveniently used withoutdilution. I However, aspreviously noted, they maybe diluted as desired with any suitablesolvent. For instance, by, mixing '75 parts by weight of anoxyalk-ylated derivative, for example, the product of Example 30 with 15parts by weight'of xylene and 10.partsby weight of-isopropyl alcohol, anexcellent demulsifier is obtained. Selection of the solvent willuvary,depending upon the solubility characteristics of the oxyalkylatedproduct, and of course will be dictated in part by economicconsiderations, i. e., cost.

As noted above, the products herein described may be used not only indiluted form, but also may be used admixed with'some other chemicaldemulsifier. A mixture which illustrates such com binationis thefollowing; T

Oxyalkylated derivative, for example, the uct of Example 30, 20%;

A cyclohexylamine salt of a polypropylated naphthalene mono-sulfonicacid, 24%;

An ammonium salt of a polypropylated naphthalene mono-s'ulfoni'c acid,24%;

' A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12%; I

A high-boiling .aromatic petroleum solvent, e,

Isoproyl alcohol, 5%. i

The above proportions are all weight percents.

Having thus described my invention what I claimas new and desire tosecure by Letters Patent, is

1. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile synthetic 1products beingcharacterprodin which R is the radicallof a glycerol etherof' a hexyl alcohol; n and n are numerals with the proviso that n and nequal a sum varying from 15 to 8.0, and n" is a whole number not over 2,and I R is the radical of the polybasic acid coon in which R is theradical of a glycerol ether of a hexyl alcohol, in which the hexylradical is that of normal hexyl alcohol; n and n are numerals with theproviso that n and 11/ equal a sum vary- 23 ing' from 15 W80, and n" isa whole number not over 2, and Ris the radical of the polybasic acid e Io'ooH- ooHw in which n has its previous significance, and with thefurther proviso that the'parent dihydroxylated compound prior toesterification be water-insoluble.

*3. A process for breaking petroleum emulsions of the wa'ter-in-oiltype: characterized by subje'cting the emulsion to the actionof ademulsifier" including hydrophile synthetic products; said hydrophilesynthetic products being characterized by the following formula:

. o 7 (HOOCLWR (OCaHo)nOR'O(C3H6O)n' R(COOHM-If in which R is the.radical of a glycerol ether of a hexyl alcohol, in which the hexylradical is that of a normalhexyl alcohol; in and n arenumerals with-theproviso that n and'n' equala sumvarying from 15 to 80, and L. isawholenumber not over 2, and R is the radical ofthe polybasic, acid ooo'H H Icoon H in which n" has its previous significance. and with the furtherproviso that the parent dihydroxylated compound prior to .esterificationbe water-insoluble and at least kerose'ne-dispersible. 4. A process forbreaking petroleum emulsions of the water-in-oil type characterized bysubjecting the emulsion to the action of a demulsifier includinghydrophile synthetic products; said 'hydrophile synthetic products beingcharacterized by the following formula:

' 7 9 I -Hoo.c R g ocanonon'omsmowi imc0011 in which Rfis the radical ofa glycerol ether of a hexyl alcohol in which the hexylradical is that ofnormal hexyl alcohol; n and n'are numerals with the proviso that n and nequal a sum varying from to 80, and n is a whole number not over 2, andR is the radical of the polybasic acid r r coon i I v in which n has itsprevious significance, said polycarboxy acid having not over 8 carbonatoms; and with the further proviso that the parent dihydroxylatedcompound prior to esterification be water-insoluble and at leastkerosene-dispersiblel 0 o (HOOC)R (OCaHa)nORQ(CsHuO)n' R(COOH) in whichR is the radical of a glycerol ether of a hexyl alcohol, in which thehexyl radical is that of normal hexyl alcohol; n and n are numerals withthe proviso that n and 11. equal a sum varying from 15 to 80, and R isthe radical of the di' carboxy acid I a coon said dicarboxy acid havingnot over .81 carbon atoms; and With the further proviso that the parentdihydroxylated compound prior to esterification be water-insoluble andat least kerosenedispersible. a

6. The process of claim 5 wherein the dicarboxy acid is phthalic acid.

'7. The process of claim 5 wherein the dicarboxy acid is maleic acid.

8. The process of claim 5 wherein the dicarboxy acid is succinic acid.

9. The process of claim 5 wherein the acid is citraconic acid. 7 I

5 wherein the dicardicarboiiy 10. The process of claim boxy acid isdiglycollic acid.

MELVIN DE GRooTEl Y REFERENCES CITED The following references are ofrecord in the file of'this patentzfl I UNITED STATES PATENTS

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPECHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIERINCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETICPRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA: